Theoretical seismic wave radiation from a fluid‐filled borehole

Abstract

This paper concerns far‐field radiation of compressional P and shear S waves into the surrounding medium from a fluid‐filled borehole in an infinite medium and tube waves propagating along a borehole, using a low‐frequency approximation. Two kinds of sources are considered: (1) a volume displacement point source acting on the axis of a borehole, and (2) a uniform radial stress source acting on the wall of a borehole. When the tube‐wave velocity is close to the shear‐wave velocity, the effect of the borehole fluid on the P‐wave radiation pattern and on the S‐wave radiation pattern is substantial.